'A little dab'll do ya' for hay sampling too

A sizeable glob in the palm of your hand was all that it took back in the "Grease" era of the 1960s for controlling a head-full of locks.

It does not take much more than that for an alfalfa producer to gain firm control of the value of a stack of hay, according to University of California, Davis Extension forage agronomist Dan Putnam.

A heaping tablespoon is all a laboratory needs to determine the feed values of a 150-ton haystack. A ground one-gram sample taken from a half pound of collected material is enough to accurately estimate the feed value of 300,000 pounds of alfalfa hay, according to Putnam.

That brings to mind a quote from a Southern California hay broker who was asked several years ago about the value of testing to determine hay quality for marketing purposes: "Kicking the trailer’s tires on a load of hay will tell you as much as a hay test will. If you need to test hay to determine its quality, you don’t belong in the hay business."

The merit of buying and selling hay on test has been a long-standing debate in California. If producers manage hay to produce high quality, will they be rewarded for it because striving for quality most likely reduces tonnage? It is a Catch 22.

Putnam says testing hay for quality to establish a market value is worth the grower’s efforts.

After all, dairymen test hay to determine its feed value for their cows. Alfalfa hay growers should do the same thing to validate the quality and value of the hay they sell to dairymen or anyone else.

Test variability

Putnam does not deny there is variability in hay test results within a lab: plus or minus 0.5 percent for crude protein (CP): 0.7 percent for acid detergent fiber (ADF) and as much as 1 percent neutral detergent fiber (NDF).

Nevertheless, Putnam said that is not enough to invalidate a grower’s efforts to establish a value on their hay by testing it, and it can be done with only a small sample.

"If sampling protocol is carefully followed, sampling variation can be reduced to an acceptable level, and the potential forage quality successfully predicted," he said.

One bale does not represent a value of a haystack no more than one sample does. Putnam said bales within a stack can range from a TDS of 54.5 to as much 62. That is why a minimum of 20 stack samples are necessary to get a representative stack sample, Putnam told those at an alfalfa meeting at Kearney Ag Center in Parlier.

And don’t sample by grabbing handfuls of hay from the outside of the stack. "In a test of seven hay lots, comparing ‘grab’ samples with 20 properly cored combined samples, the grab sample was always lower quality than the proper sample," Putnam reported.

When sampling, don’t mix lots, fields, cuttings or hay types.

Sample as close to feeding or point of sale as possible.

Use a sharp coring device with a diameter of three-eighths inch. There is a wide variety of hay sampling tools ranging from hollow golf club shaft to sophisticated probes with hay sample receptacles.

Probe random bales, sampling butt ends between strings and wires — not near the edge.

The length of the probe should be 12 to 24 inches. Research has shown deeper samples, even in large bales, are no more valid than the shallow probes.

"Sampling a large number of locations and bales throughout the stack to create a composite sample is a key aspect of representing the full variation in a hay lot," said Putnam.

Half pound sample

The total sample amount should be about a half pound. Seal a sample in a plastic bag. Protect it from heat and deliver it to a lab as soon as possible. Refrigerating a sample before delivering it is even better.

"Don’t toss a sample on the dashboard of your pickup and drive around a day before delivering the sample to the lab," he reminded producers.

Choose a National Forage Testing Association lab to grind and analyze the sample, Putman said.

Kicking the tires of a hay truck definitely will not determine the quality of the alfalfa loaded on it, but Putnam is convinced that proper sampling and analysis of a haystack is worth the effort.